1. Field of the Invention
The present invention relates generally to a thermal module, and more particularly to a thermal module capable of providing excellent heat dissipation effect for a heat source over which the heat is non-uniformly distributed.
2. Description of the Related Art
There is a trend to develop thinner and thinner electronic apparatuses nowadays. The ultra-thin electronic apparatus includes miniaturized components. The heat generated by the miniaturized components of the electronic apparatus has become a major obstacle to having better performance of the electronic apparatus and system. In order to solve the heat dissipation problem of the components in the electronic apparatuses, various vapor chambers and heat pipes with better heat conduction performance have been developed.
The vapor chamber has a rectangular housing and capillary structures formed on inner wall face of the chamber of the housing. A working fluid is filled in the housing. One face (the evaporation section) of the housing is attached to a heat generation component (such as a central processor, a Northbridge/Southbridge chipset or a transistor) to absorb the heat generated by the heat generation component. Accordingly, the liquid working fluid in the evaporation section of the housing evaporates into vapor working fluid to transfer the heat to the condensation section of the housing. The vapor working fluid is cooled and condensed into liquid phase. Under gravity or capillary attraction of the capillary structures, the liquid working fluid flows back to the evaporation section for next vapor-liquid circulation. Accordingly, the heat can be spread and dissipated.
The working principle of the heat pipe is similar to that of the vapor chamber. Metal powder is filled into the interior of a hollow circular tube. Then the metal powder is sintered to form an annular capillary structure on inner wall face of the heat pipe. Then the heat pipe is vacuumed and a working fluid is filled into the heat pipe. Finally, the heat pipe is sealed to form the heat pipe structure. The liquid working fluid in the evaporation section of the housing is heated to evaporate into vapor working fluid. The vapor working fluid diffuses to the condensation end to transfer the heat to the condensation end. During the diffusion, the vapor working fluid is gradually cooled and condensed into liquid phase. Under capillary attraction of the capillary structure, the liquid working fluid flows back to the evaporation section for next vapor-liquid circulation.
In comparison with the vapor chamber, the heat pipe conducts heat in a different manner. The vapor chamber serves to two-dimensionally face-to-face transfer heat, while the heat pipe serves to one-dimensionally transfer heat.
In generally, the heat generated by the chip is concentrated on the surface. However, the heat may be non-uniformly distributed over the surface. This is because the integrated components of the chip are arranged in the chip by different densities. It has become a critical topic how to more efficiently dissipate the heat non-uniformly distributed over the surface of the chip to achieve better heat dissipation effect for the high-power electronic components.